AUTHORS: Ashley G. McDonald, Southern Illinois University; Jennifer R. Schultze, Southern Illinois University; Clayton K. Nielsen, Southern Illinois University; F. Agustin Jimenez, Southern Illinois University
ABSTRACT: Zoonoses are attributed to approximately 75% of emerging infectious diseases. Contraction of zoonotic infections is linked to urbanization, as land development increases the probability of human interaction with wildlife. Omnivorous animals such as raccoons thrive in urban settings due to the abundance of anthropogenic resources such as food and shelter. Racoons are the definitive host of zoonotic pathogens, including the heteroxenous raccoon roundworm (Baylisascaris procyonis); raccoon synanthropic habits bring these pathogens near human dwellings. The goal of this study is to assess the influence of raccoon abundance on the prevalence of raccoon roundworm in 5 study areas in northern Illinois representing a rural-urban gradient. Raccoons (n=287) were captured and removed from sites by collaborators during April-June 2022-2024. Upon necropsy, intestinal tracts were examined to determine raccoon roundworm prevalence. Capture per unit effort (CPUE), a measure of wildlife population abundance, was calculated as the number of raccoons captured per 100 nights of capture effort at each site. A logistic regression was used to investigate the relationship between raccoon abundance and raccoon roundworm prevalence. Raccoon roundworm prevalence decreased with increased raccoon abundance (X2=4.37, P=0.036). Counterintuitively, our findings suggest that disease risk decreases with increasing raccoon abundance, which implies that population reduction of raccoons in areas of high abundance might be an ineffective tool to reduce the risk of roundworm infection to the human population. Land-use can also impact parasite prevalence, as the availability of anthropogenic resources can influence raccoon population dynamics. Future analyses examining the relationship between land-use, raccoon roundworm prevalence, and raccoon abundance might provide a better understanding of the influence of population demographics on raccoon roundworm prevalence.
